There are various methods known in the art to prepare linear olefins.
Such process is disclosed in U.S. Pat. No. 4,579,986. This U.S. patent discloses a process for the preparation of linear C10–C20 olefins, which process comprises preparing a mixture of hydrocarbons substantially consisting of linear paraffins by:                (a) contacting a mixture of carbon monoxide and hydrogen at elevated temperature and pressure with a cobalt-containing catalyst,        (b) separating from the paraffin mixture thus prepared a heavy fraction which consists substantially of C20+ paraffins, and        (c) converting at least this heavy fraction (a “wax”) by mild thermal cracking into a mixture of hydrocarbons which consists substantially of linear olefins and contains the desired C10–C20 olefins.        
Although the wax cracking method according to U.S. Pat. No. 4,579,986 performs satisfactorily, there is still room for improvement. Particularly if the starting point is to produce an olefin-containing feed which can be used as (part of) the feedstock for a hydroformylation reaction stage to produce linear detergent and plasticizer alcohols, the method according to U.S. Pat. No. 4,579,986 can be improved. Namely, linear plasticizer alcohols typically contain from 7 to 11 carbon atoms, while linear detergent alcohols typically contain 12 to 15 carbon atoms. Accordingly, any hydrocarbon fraction produced to serve at least partly as the source of hydroformylation feedstocks should contain a significant portion of C6 to C14 olefins, at least 80% by weight, but preferably at least 85% by weight, of which consists of the corresponding linear α-olefins. It was found that by hydrogenating the wax feed prior to subjecting it to the mild thermal cracking treatment very high quality C6 to C10 and C11 to C14 linear α-olefins are produced: the C6 to C14 olefins produced (contained in a mixture of C5+ olefins) consist for more than 80% by weight of C6 to C14 linear α-olefins.